Interbody fusion device

Abstract

Technologies are generally provided for a spinal fusion device to achieve interbody fusion and maintain intervertebral spacing. The spinal fusion device includes at least two wedge-shaped intervertebral implants (IVIs) configured to be inserted between adjacent vertebrae, such that a thin end of each IVI is positioned toward a midline of the vertebrae, and a thick end of each IVI is positioned substantially flush with outer surfaces of the vertebrae. A lower surface of a superior vertebral body and an upper surface of an adjacent inferior vertebral body are resected to accommodate the IVIs, and a portion of an intervertebral disc (IVD) is also removed to facilitate insertion of the IVIs. The IVIs are inserted in substantially opposite positions to each other between the vertebrae, and an interconnecting member is inserted to connect the IVIs. The interconnecting member passes through residual IVD to stabilize the IVIs in position between the vertebrae.

What is claimed is: 
     
       1. A spinal fusion device to achieve interbody fusion and maintain intervertebral spacing, the spinal fusion device comprising:
 a substantially wedge-shaped first intervertebral implant and a substantially wedge-shaped second intervertebral implant (IVI) configured to be inserted bilaterally between a first vertebra and a second vertebra, and to displace at least a portion of an intervertebral disk (IVD) between the first and second vertebrae, wherein a thin end of each IVI is configured to be positioned toward a midline of the first and second vertebrae and a thick end of each IVI is configured to be positioned to be substantially flush with outer surfaces of the first and second vertebrae, wherein a slope from the thin end to the thick end of the first and second IVIs is adjustable after insertion of the first and second IVIs between the first and second vertebrae to increase an intervertebral distance between the first and second vertebrae. 
 
     
     
       2. The spinal fusion device of  claim 1 , wherein the first IVI and the second IVI are configured to be positioned substantially opposite and parallel to each other such that the thin ends are configured to be positioned next to each other near a midline of the first and second vertebrae. 
     
     
       3. The spinal fusion device of  claim 1 , wherein the first IVI is configured to be positioned at an anterior position between the first and second vertebrae and the second IVI is configured to be positioned at a posterior position between the first and second vertebrae in relation to a midline of the vertebrae. 
     
     
       4. The spinal fusion device of  claim 1 , wherein the first IVI is configured to be positioned at a first lateral position between the first and second vertebrae and the second IVI is configured to be positioned at a second lateral position between the first and second vertebrae in relation to a midline of the vertebrae. 
     
     
       5. The spinal fusion device of  claim 1 , wherein a lateral cross section of upper surfaces of the first and second IVIs is configured to match a lateral cross section of an inferior surface of the first vertebra and a lateral cross section of lower surfaces of the first and second IVIs is configured to match a lateral cross section of a superior surface of the second vertebra. 
     
     
       6. The spinal fusion device of  claim 1 , wherein a change in thickness from the thin end to the thick end of the first and second IVIs is selected to match an anatomy of an intervertebral distance between the first and second vertebrae. 
     
     
       7. The spinal fusion device of  claim 1 , wherein the slope from the thin end to the thick end of the first and second IVIs is selected to match an anatomy of a slope from an interior portion of the first and second vertebrae to an exterior portion of the first and second vertebrae. 
     
     
       8. The spinal fusion device of  claim 1 , wherein the slope from the thin end to the thick end of the first and second IVIs is selected to match a slope of a resected plane of the first and second vertebrae from an interior portion of the first and second vertebrae to an exterior portion of the first and second vertebrae. 
     
     
       9. The spinal fusion device of  claim 1 , wherein a slope of the first and second IVIs from anterior to a posterior position is capable of being modified to match a desired kyphosis and/or lordosis of a spine. 
     
     
       10. The spinal fusion device of  claim 1 , wherein the first and second IVIs are composed from one or more of: a metal material, a polymer material, a ceramic material, and a bio-absorbable material. 
     
     
       11. A method to achieve interbody fusion, the method comprising:
 inserting first and second intervertebral implants (IVIs), each being substantially wedge-shaped and tapered from a thick end to a thin end, between first and second vertebrae displacing at least a portion of an intervertebral disk (IVD) between the first and second vertebrae; and 
 positioning the thin end of each IVI toward a midline of the first and second vertebrae such that the thick end of each IVI is positioned to be substantially flush with outer surfaces of the first and second vertebrae, wherein a slope from the thin end to the thick end of the first and second IVIs is adjustable after insertion of the first and second IVIs between the first and second vertebrae to increase an intervertebral distance between the first and second vertebrae. 
 
     
     
       12. The method of  claim 11 , further comprising:
 positioning the first IVI and second IVI in a substantially opposite and parallel position to each other such that the thin ends are positioned next to each other near a midline of the first and second vertebrae. 
 
     
     
       13. The method of  claim 11 , further comprising:
 inserting at least one interconnecting member configured to connect the first IVI with the second IVI and to pass through a residual IVD to stabilize the first and second IVIs in position between the first and second vertebrae. 
 
     
     
       14. The method of  claim 13 , further comprising:
 reducing a distance between the first and second IVIs to increase a displacement between first and second vertebrae. 
 
     
     
       15. The method of  claim 13 , further comprising:
 integrating a bone graft with the interconnecting member to promote bone growth between the first and second vertebrae. 
 
     
     
       16. A system for achieving interbody fusion, the system comprising:
 a substantially wedge-shaped first intervertebral implant and a substantially wedge-shaped second intervertebral implant (IVI) configured to be inserted bilaterally between a first and second vertebrae displacing at least a portion of an intervertebral disk (IVD) between the first and second vertebrae, wherein a thin end of each IVI is configured to be positioned toward a midline of the first and second vertebrae and a thick end of each IVI is configured to be positioned to be substantially flush with outer surfaces of the first and second vertebrae; and 
 an interconnecting member configured to connect the first IVI with the second IVI and to pass through the residual IVD to stabilize the first and second IVIs in position between the first and second vertebrae, wherein a slope from the thin end to the thick end of the first and second IVIs is adjustable after insertion of the first and second IVIs between the first and second vertebrae to increase an intervertebral distance between the first and second vertebrae. 
 
     
     
       17. The system of  claim 16 , wherein the first and second IVIs are composed from a porous material for promoting bone growth between the first and second vertebrae through the first and second IVIs, and wherein a bone graft is integrated with the porous first and second IVIs to promote bone growth between the first and second vertebrae through the first and second IVIs. 
     
     
       18. The system of  claim 17 , wherein the bone graft is one or more of: an autograft, an allograft, a bone graft substitute, and a bone morphogenic protein. 
     
     
       19. The system of  claim 16 , wherein at least a portion of the interconnecting member is composed from a porous material to promote bone growth between the first and second vertebrae through the first and second IVIs and the interconnecting member.